Carburetor



A. COX

CARBURETOR 2 Sheets-Sheet 2 Filed March 5,; 1925 Patented Dec. 29, 1925.

i UNITED STATES ARTHUR COX, F IOLTON, NEAR BIRMINGHAM, ENGLAND.

'oAnBUnnron Application mea March 5, 1925-. serial No. 13,231.

. To all whom it may concer/fz: l

` Be it known that I, .ARTHUR COX, subject of the King of Great Britain,residing at Harlech, farwick Road, Olten, near Birmingham, England, haveinvented a` certain new anduseful Carburetor, of which the followingis aspecification.

My invention has reference to carburetors of the kind described in thespecification of myy United States Letters Patent dated the 31st day ofAugust 1920 No. 1,351,624,v

wherein a: nozzle discharges into a branch passage which conveys thefuel and the primary air into'a main air-passage, and the fuel-deliveryfrom the said nozzle is varied vby .regulating an admission oit air intothe said branch by mea-ns of a rotary valve v located between the nozzleand the main passage and operated byor from the throttle valve.`

The object of my said invention is to provide for the embodiment in abarrel-throttle carburetor of the above-'mentionedtype, of an idlingnozzle for supplying mixture to the engine when the throttle-valve isclosed.

To realizey this, I propose, according to my present invention,to'utilizethe nozzle lthat discharges into the primary air-branch as themain or normal-running nozzle, and to provide an idling nozzle fordelivering fuel or mixture into the main passage on the engine side ofthe throttle valve when the main nozzle ,is out of action. Also I applyto or detachably mount upon the 'fixed member or casing of the valvethat controls the main nozzle discharge, a nozzle-housing in "which boththe main nozzle and the idling nozzle are fitted, whilst I also use inVcombination with such a nozzle system, a fuel 'or mixture receptionpassage which is formed in the throttle chamber in concentric relationto the throttle axis and has communication, `on the one hand, with theidling nozzle by a conduit passage located outside the throttle-operatedvalve that' controls :he

` main nozzle, and on the other hand, with the present invention andtaken on line 1-1 ofFigure 2. i y f v Figure 2 is an elevation of thatside of the carburetor on which the nozzle and the primary air-intakeare located.

Figure 3 is a plan, partly inhorizontal section on line 3-3 of Figure 4.

Figure 4t is an elevation of the carburetor looking from the right-handside of' Figure 2 and showing the engine side ofthe throttlevalve; thisvalve being in its closed position.

Figure 5 is a sectional elevation showing the fuel-connections betweenthe idling nozzle and the engine side of the throttlegthe throttle beingshown slightly opened.

Figure 6 is a vert-ical section on line 6-6 of Figure 5.

Figure 7 is a vertical section on line 7 7 of Figure 3.

Figure 8 is an enlarged sectional detail of the idling nozzle.

Figure 9 is an elevation of the throttlebarrel separately.

The same letters` of reference indicate correspondingpartsin the severalfigures.

' In the construction illustrated, the part a (hereinafter referredto`as the nozzle body) that housesj the' nozzles is vdetachably secured byscrews or the like to a iiange or seating a on the outer end `of thelixed ported sleeve e2 that surrounds the primary kair branch c andcontains the ported member c of the valve which controlsthe fueldelivery of the nozzle b (hereinafter referredto as the main nozzle),and rotates with the throttle-valve. Both the main and the idlingnozzles b, d are removably mounted `in chambers in the nozzle body, andthe idling nozzle takes its fuel from a supply passage e? connected withthe iioat chamber (notshown) of the'device. The idling nozzle comprisesa detachable and interchangeable nipple formed at the inner end of ascrew threaded and axially-bored plug d2; the interior of said nipplehaving communication both with the idling fuel-passage d3 and with anair-intake hole d* which is drilled in a cap d5 that is normally appliedto the `outer end of the plug. This nipple is also drilled with radialoutlet passages d communicating with an annular clearance d that isprovided between the nipple and its chamber d, and with which anexternal conduit e of relatively small bore connects, the conduit eextending to the throttle-chamber of the carburetor, where itcommunicates withv a reception channel, groove or passage that is formedbetween an end of the throttle-barrel, and the corresponding end of thethrottle-cham ber, in concentric relation to the throt-tleaxis. Forinstance, as in the illustrated construction, that end of thethrottle-barrel f nearest t-he nozzle body is formed with an annularstep f of smaller diameter than the tln'ottle-chamber so as to providean annular passage or reception chamber g into which the tube e leads sothat this reception chamber is in communication with theexternally-located idling nozzle in all positions of the throttle.

From the reception chamber fg, a hole h is l drilled into the throttlebarrel, parallel with the axis ofthe latter, and from this hole one ormore small ports lead out onto the periphery of the barrel on the engineside ot the throttle.

In the device shown in the drawings, two such ports t, 71,2 areprovided, and these are so arranged that when the throttle is closed`(see Figure 4) only the one port 7L is uncovered and in communicationwith the induction passage on the engine side of the throttle barrel andit is from this port 7L that Jruel is then induced :trom the idlingnozzle by the depression set up by engine suction in the .inductionpassage between the closed throttle and the engine. As regards thesecond port h2, this is uncovered or brought into communication with theinduction passage (as shown in Figure by the initialmoveinent of thethrottle barrel from the full-closed position and its effect is tomaintain ,the fuel supply from the idling nozzle during .such initialthrottle opening and to prevent` the cutting out of the idling nozzlebefore the main nozzle is in effective operation. That is to say, when,with, the engine idling, the throttle is slightly opened from thefully-closed position, the consequent Iopening of connnunication betweenthe atmosphere and the induction passage brings about a `drop in thedepression produced by engine suction within the said passage, but sinceboth ports 7L', h2 are uncovi cred bythe throttle movement, this reduceddepression is etl'ective upon a port area double lthat which obtainswhen the throttle is closed, and by the action of the reduceddepressionl on the doubled port area effective suction on the idlinglnozzle is maintained until the throttle is so far opened as to bringthe main nozzle into action. Irregular engine running during the changeover from the 'idling to the main nozzle is thus obviated.

Having described my invention, what I claim and desire to secure byLetters Patent is l. A carburetor having a main body provvided with athrottle chamber, a barrel type throttle rotatably iitted in saidchamber, a primary air tube discharging into said throttle, a housingfixed on 'said tube, a main nozzle in said housing discharging into saidtube, means `for controlling the operation ot the main nozzle includinga rotary valve carried by the throttle, an idling nozzle in the housing,said throttle having an idling mixture discharge port and also having apassage leading to said port, an idling mixture reception chamberconcentric with the axis ot.' the throttle and located between the endot the throttle and the throttle housing, said reception chambercommunicating with said passage in the throttle, and a separate conduithaving a small bore and extending between the idling nozzle and thereception chamber. I

2. A carburetorhaving a main body provided with a throttle chamber, abarrel type throttle rotatably fitted in said chamber, a primary airtube discharging into said throttle, a housing lixed on said tube, amain nozzle in said housing discharging into said tube, means forcontrolling the opy eration of the main nozzle including a rotary valvecarried by the throttle, an idling nozzle in the housing, said throttlehaving a plurality `of idling mixture-discharge ports in its periphery,lone of said idling mixture discharge ports being open to the engineside of the throttle when the throttle is closed and both of said idlingmixture dischargeA AIn testimony whereof he hereunto atfixes hissignature.

ARTHUR COX.

Cil

